A fractal is a geometric structure that can repeat itself towards infinity. Zooming in on a fragment of it, the original structure becomes visible again. In biological systems, fractal structures can be found everywhere – bronchial trees, vasculature, and nerve cells. These amazing structures can provide a specific interfacial contact mode that is highly efficient for absorbing sunlight, transporting nutrition, exchanging oxygen and carbon dioxide, and signal transduction. Due to their attributes, artificial fractal structures (read more: "Building 3D fractals on a nanoscale") have attracted considerable scientific interest for their appealing applications in fractal antennas, solar cells, and biosensors.